The present invention relates generally to medical apparatus and methods and more particularly to devices and methods for cushioning or padding the surface of compression plates applied to body parts for purposes of obtaining x-ray films for example mammography, or other scans of compressed tissue.
Currently, in the case of mammography, a patient""s breast is placed under compression by opposing plates attached to a mammography machine. Once under compression an x-ray is taken to determine the presence or absence of suspect lesions in the breast tissue (e.g. calcifications, tumors). Approximately 25 million screening mammograms are performed yearly, which is estimated to be only a 50% compliance rate among potential patients, meaning that number would double if more patients complied with the recommended screening regime. One of the more common complaints from mammography patients is discomfort during compression of the breast. Most patients can only tolerate up to 10-11 compression units. The current legal limit for clinical mammography is 16-18 units. A device which would reduce discomfort could likely improve compliance for screening.
An important reason for compressing the breast during mammography is to provide a thinner cross section of tissue for the x-rays to pass through. When the breast is compressed, it provides optimal imaging of the tissue abnormalities with the lowest possible dose of x-ray radiation to the patient. Furthermore, during a mammogram, it is important for the x-ray plate to be free from radiopaque material, so that the diagnostic film, once processed, can give the physician the best possible picture of the tissue and any abnormalities.
Although patients may tolerate the pain during compression, there is a need for improved devices and techniques to provide better screening outcomes by enabling the use of higher compression force, and by providing increased patient comfort during mammograms thereby positively impacting patient compliance with mammographic screening and ultimately impacting early detection of cancer and improving patient survival.
Such improved devices must be radiolucent and made of a relatively homogeneous material to avoid striations or other variations on the resulting x-ray image, have a low profile to allow for correct positioning of the breast in the mammography machine, be easily cleaned or disposable for sanitary reasons, and provide structural support and tactile comfort to the patient (both soft to touch and providing a less harsh or xe2x80x9ccoldxe2x80x9d surface). In addition, such improved devices will permit the use of higher compression forces to be applied to the breast during mammograms without the patient reaching her tolerance level for discomfort, resulting in a thinner tissue section, better image quality, and reduced x-ray dose to the patient.
It is an objective of the present invention to provide greater patient comfort thereby increasing screening compliance (e.g. patient willingness to have more regular mammograms by reducing discomfort of the procedure). Greater patient comfort also reduces the risk of patient movement (voluntary or involuntary). Motion artifact, caused by patient movement or slippage of the tissue, can result in loss of clarity of the mammographic image. It is a further objective of the present invention to allow for the use of an increased compressive force, for example, up to 16-18 compression units or more thereby providing for a thinner cross-section of breast tissue during the mammogram resulting in an enhanced ability to detect abnormalities in the mammographic image. These objectives are met by the design and use of the present invention.
Various patents have issued illustrating inventions in the field of mammography and comfort during x-ray imaging. For example, in the field of mammography, U.S. Pat. Nos. 3,963,933, 4,691,333, 4,943,986, 5,189,686, 5,553,111 and 5,398,272 describe various fixtures useful for breast compression. Further, patents have issued describing devices for increasing comfort during general x-ray procedures, such as U.S. Pat. No. 5,226,070 (radiolucent x-ray mat), U.S. Pat. No. 5,081,657 (buckey warmer for mammography machine), U.S. Pat. No. 5,541,972 (disposable padding device for use during mammography) and U.S. Pat. No. 5,185,776 (padded cover for x-ray cassette).
According to the present invention, improved methods and apparatus are provided for cushioning or providing other patient comfort surfaces on devices used for compressing the patient""s tissue, such as radiography machines, fluoroscopy units, mammography units and the like. In particular a pad element is provided for releasable attachment to at least one surface of a compression device to be used under x-ray, or other imaging modality.
In a preferred embodiment of the present invention a pad assembly is provided consisting of a pad element, an adhesive layer and a release paper layer allowing for temporary attachment to the applied surface (either the mammography paddle, x-ray plate or directly to the patient""s skin).
An alternative embodiment of the present invention includes a reusable cushioned paddle configured of a self-skinned foam to allow for easy cleaning between patients. This embodiment may be replaceable after many uses or formed integrally wherein the padded surface and the compression paddle are assembled as one unit.
The present invention may also incorporate a dispensing unit for access to single pads for single use.